sunrpc: Pushdown the bkl from ioctl

Pushdown the bkl to rpc_pipe_ioctl.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Nfs <linux-nfs@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>

net/sunrpc/rpc_pipe.c

@@ -27,6 +27,7 @@
 #include <linux/workqueue.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/sunrpc/cache.h>
+#include <linux/smp_lock.h>
 
 static struct vfsmount *rpc_mount __read_mostly;
 static int rpc_mount_count;
@@ -309,8 +310,7 @@ rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 }
 
 static int
-rpc_pipe_ioctl(struct inode *ino, struct file *filp,
-		unsigned int cmd, unsigned long arg)
+rpc_pipe_ioctl_unlocked(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct rpc_inode *rpci = RPC_I(filp->f_path.dentry->d_inode);
 	int len;
@@ -331,13 +331,25 @@ rpc_pipe_ioctl(struct inode *ino, struct file *filp,
 	}
 }
 
+static long
+rpc_pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	long ret;
+
+	lock_kernel();
+	ret = rpc_pipe_ioctl_unlocked(filp, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}
+
 static const struct file_operations rpc_pipe_fops = {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.read		= rpc_pipe_read,
 	.write		= rpc_pipe_write,
 	.poll		= rpc_pipe_poll,
-	.ioctl		= rpc_pipe_ioctl,
+	.unlocked_ioctl	= rpc_pipe_ioctl,
 	.open		= rpc_pipe_open,
 	.release	= rpc_pipe_release,
 };